Development and Validation of the Vending Evaluation for Nutrient-Density (VEND)ing Audit

• Main Authors: Tanya M. Horacek, Elif Dede Yildirim, Melissa Matthews Schreiber, Carol Byrd-Bredbenner, Sarah Colby, Adrienne A. White, Karla P. Shelnutt, Melissa D. Olfert, Anne E. Mathews, Kristin Riggsbee, Lisa Franzen-Castle, Jesse Stabile Morrell, Kendra Kattelmann
• Format: Article
• Language: English
• Published: MDPI AG 2019-02-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: vending machines; food environment; snacks; beverages; nutrient-density score
• Online Access: https://www.mdpi.com/1660-4601/16/3/514

<i>Background:</i> This paper describes the development and validation of the Vending Evaluation for Nutrient-Density (VEND)ing audit to comprehensively evaluate vended products based upon healthfulness, price and promotion, and machine accessibility. <i>Methods:</i> A novel vending nutrient-density score was created to determine the healthfulness of vended snack/beverage products. Field tested in United States colleges, VENDing audit (&#8721;nutrient-density + 10 &#215; % healthy products) and Support sub-scores (price + promotion + accessibility) were calculated for snack/beverage machines. Higher scores indicate more healthful vending options and supports for choosing healthfully. Nutrition Environment Measures Survey-Vending (NEMS-V) was used to validate the nutrient-density score for a sub-sample of machines. Sensitivity and specificity were computed by comparing the number of healthy snacks/beverages determined by NEMS-V and the VENDing nutrient-density scores. <i>Results:</i> Researchers conducted the VENDing audit on 228 snack/beverage vending machines at 9 universities within the United States and used both VENDing and NEMS-V on 33 snack and 52 beverage vending machines. Mean VENDing audit scores were 4.5 &#177; 2.0 (2.6, 3.4) and 2.6 &#177; 2.0 (0, 12) for snack/beverage machines, respectively. The number of products considered healthy assessed with both the VENDing nutrient-density scores and the NEMS-V were positively correlated for beverages (<i>r</i> = 0.687, <i>p</i> &lt; 0.001) and snacks (<i>r</i> = 0.366, <i>p</i> &lt; 0.05). The sensitivity was excellent for beverages (0.83) and moderate for snacks (0.69); while the specificity was moderate for both beverages (0.66) and snacks (0.50). <i>Conclusions:</i> The VENDing audit uses unique, valid, and reliable nutrient-density scoring to evaluate snacks/beverages along a continuum of healthful criteria and comprehensively evaluates the full vending environment.